1. Field of the Invention
This invention relates to the making of composite articles with different metallic powders, and to the method of forming such composite articles.
2. Description of the Prior Art
The presently known pertinent prior art in powder metallurgy, in relation to load bearing composites, have two characteristically different metallic powders joined to form a single composite article, is represented by a group of U.S. Pat. Nos. 3,665,585, 3,762,881, 3,768,327, 3,772,935, 4,054,449 and 4,145,798 which is the work of William M. Dunn and co-inventors between 1970 and 1977. That work in the field was preceeded by the work of John Haller disclosed in U.S. Pat. Nos. 3,320,663 and 3,324,544 of 1967. This development of powder metallurgy for making load sustaining composite articles is believed to stem from the need to develop articles at significantly lower costs. Heretofore, load sustaining articles had been machined from metallic blanks followed by suitable heat treatment. A high rate of scrap parts has resulted, so there has been good reason to pursue powder metallurgy to realize savings therefrom.